DTC 1 ABS Pump Motor Over-Run

DIAGNOSTIC PERIOD
During initial & individual diagnosis.

DESCRIPTION OF DIAGNOSIS
The Anti-lock Brake System (ABS) indicator light is turned ON when the pump motor relay ON signal is detected for more than 40 seconds while the ABS is not functioning.

PROBABLE CAUSE
- Air mixed in the ABS brake fluid.
- Pressure switch stuck OFF
- Open circuit between the pressure switch and ABS control unit
- Open circuit in the Pressure switch (P-SW) circuit between the pressure switch and body ground, or a poor ground
- Drop in pump discharge volume
- Leaking outlet valve
- Leaking relief valve
- ABS brake fluid leakage
- Faulty ABS control unit

Refer to Diagnostic Charts. DTC 1